have kittens idiom Trending Now: More Trending: charlatan lowlife kakistocracy slimeball salacious SEE ALL See What's Trending Now See More Trending Words What's Trending Now More Trending Words charlatan 'faker or fraud' lowlife 'a person of low moral character' kakistocracy 'government by the worst people' slimeball 'a morally repulsive or odious person' salacious 'arousing or appealing to sexual desire' SEE ALL Time Traveler! Explore the year a word first appeared Definition of have kittens British, informal : to become very nervous or upset about something They had kittens when they saw the mess we made. Word by Word Definitions kitten play kittens : a young cat : to give birth to kittens See the full definition of kitten Seen and Heard What made you want to look up have kittens? Please tell us where you read or heard it (including the quote, if possible). show hide